Locomotive construction



April 1944- w. E. WOODARD IETAL 2,346,716

LOCOMOTIVE CbNSTRUGTION Original Filed Aug. 6, 1938 9 Sheets-Sheet 1 IN VENTORS E. WWW!) H. FILANDER ATTURNEYS w. E. WOODARD ETAL 2,346,716

L'OCOMOTIVE CONSTRUCTION April 18, 1944.

8: k .3 xx 3 x April 18,1944. w, WOQDARD ETAL 2,346,716

LOCOMOTIVE CONSTRUCTION Original Filed Aug. 6, 1938 9 Sheets-Sheet 3 INVENTORS WILLIAM E. WOUDARL" ARTHUR H. FILANDER BY ATTORNEYS April 1944. w. E. WQODARD ET AL 2,

LOCOMOTIVE CONSTRUCTION Original Filed Aug. 6, 1958 9 Sheets-Sheet 4 IN VENTURS WILLIAM E. WOOD/1RD ARTHUR H. Fl NDER April 18, 1944. w. E. WOODARD ETAL 2,346,716

LOCOMOTIVE CONSTRUCTION Original Filed Aug. 6, 1938 9 Sheets-Sheet 5 April 18, 1944.. W E, WOODARD ETAL 2,346,716

LOCOMOTIVE CONSTRUCTION Original Filed Aug. 6, 1958 9 Sheets-Sheet 6 1 N VEN TURS WILLIAM E. WGODARD ARTHUR H. F/L NDER April 8, 1944. w. E. oob-ARD M. 2,346,716

LOGOMOTIVE CONS TRUGTION Original Filed Aug. 6, 1938 9 Sheets-Sheet '7 INVENTORS WILLIAM E. WOOD/1RD ARTHUR H. F ILANDER ATTORNEYS April 18, 1944. w. E. WOODARD ET AL LOCOMOTIVE CONSTRUCTION Original Filed Aug. 6, 1938 9 Sheets-Sheet 8 I N VEN TOR 5 WILLIAM E. WOUDARD ARTHURH FILANDER BY W ATTORNEYS IIIJ April. 18, 1944. w. E. WOODARD- ET AL LOCOMOTIVE CONSTRUCTION Original Filed Au fe, 1938- 9 Sheets-Sheet 9 v r a my Mm Q atented Apr. 18, 1944 STATES ATENT OFFICE MCOMOTIVE CONSTRUCTION and Original application August 6, 1938, Serial No. 223,528. Divided and this application Apt 15, 1941, Scrlai No. M63962 12 Glaims,

Field of invention This invention relates to locomotive construction, and more particularly to the locomotive boiler and to the cooperative relation of the steam evaporating and collecting means and the boiler, shell to each other and to the remainder of the locomotive; the major aspects of the invention being related to water-tube locomotive boiler construction adapted for rapid water circulation as by forced-circulation pumps. This case is a division of our application No. 223,528, filed August 6, 1938, now Patent No. 2,318,040, granted May 4, 1943.

Ihe nature, objects and advantages of the invention will be best understood after a brief reference to existing locomotive design.

Problems to be overcome than 350 pounds per square inch, even with the advent of boiler plates and sheets formed from alloy steels of high tensile strength. A few attempts have been made to overcome the inherent limitations of the ordinary type of boiler, by inserting water tube evaporating units in some of the fiues or in the fire-box, or by utiliz-v ing a plurality of upright water tubes in conjunction with upper and lower longitudinallyextending drums, but these modifications have not met with general acceptance, even though in essential principle the water tube boiler is theoretically capable of increased capacity for a given size and weight, and higher operating pressures.

Objects and advantages of the invention I One of the primary purposes of the present invention is to overcome the above mentioned and other problems and disadvantages of customary locomotive practice, and in general to make feasible the employment of higher bo ler pressures and/or the utilization on a large scale ofwater tube evaporating surfaces in a 1ocomo-' tive boiler, whereby tosecure substantial improvements in economy, efllclency and steaming capacity within given limitations of space, weight, safety, first cost and maintenance.

Another object of the invention is to provide a locomotive boiler adapted to substantially increase the volume of the combustion space and/or the gas flow area, within locomotive and fire-box structures of given outside dimensions, particularly for improvement of the efllciency of combustion and of heat transfer, whereby it may also be practically feasible to install pulverized fuel burning equipment in locomotives.

A further object of the invention is to'render the locomotive boiler design more flexibly adaptable to existing limitations'of proportion and size and also to the preferred design criteria of the locomotive chassis and other parts.

Still other objects of the invention are to increase thesafety factor in locomotive operation, particularly by reducing the risk of the boiler running dry and also by reducing the hazard incident to boiler leaks or rupture if such should occur; to greatly increase the circulation in the boiler, and to reduce the detrimental efiects of bad water delivered to the boiler, and thus to prolong the time between boiler clean-out periods.

In accomplishing the foregoing, the invention further contemplates the provision of improved boiler steaming and circulating means, associated with a metallic housing or structural shell, wholly or in large part formed as a substantially air-tight enclosure and support for'the various other parts of the water tube boiler, said structural shell being preferably water-cooled but not subjected to the boiler pressure, the said shell preferably extending substantially throughout the length of the locomotive and arranged to enclose, in a gnerally longitudinally serial order, most or all of the following locomotive boiler elements: the combustion space, the main body of the evaporating elements, the superheating units, and the smoke-box space.

The invention further contemplates, especially in locomotive boilers of the water tube type: the subdivision of the evaporating urface into a plurality of units which are preferably coupled to headers or the like and are individually removable and replaceable, and more particularly the provision of a plurality-of water containing boiler units of the convection and/or radiantly heated type, which are separately handleable with respect to each other and to one or more; associated superheater units: the utilization of certain of said units, formed as water tubes which may have longitudinally extending external fins thereon, in closely spaced relation againstthe inside surfaces of the enclosing strubtural shell zone, the tubular elements of said units bein disposed either longitudinally or in vertical longitudinal planes in such manner that the fuel and flame stream and the hot gases pass generally in longitudinal parallel paths, whereby efficient heat transfer is secured and a minimum of scouring or grinding of the water 'tubes by the cinders occurs.

Still further, as to the boiler elements proper, the invention involves: the formation of most or all of the radiant and convection heating surface in the shape of tubes of relatively small diameter, located within said shell, to which the water is fed through headers and from which the water is taken by other heads, said headers being prefer ably located largely outside of said shell; the provision of a plurality of larger diameter drums which extend vertically and are located in longitudinal series outside of said shell along ea'ch side of the latter, to which drums the outlet headers deliver and from.which the steam is drawnfor delivery to the locomotive cylinders, preferably by way of superheater elements located within the shell; provision for rapid circulation of water in said tube units, as by means of one or more circulating pumps, there being cross-connections when a plurality of pumpstare employed, in order that a complete circulation throughout the boiler be maintained even upon failure of one of the Pumps: and the connection of the feed water delivery means from the tender to the tubular boiler in such manner that the feed water delivstructural and operational, which will appear from the accompanying drawings of a preferred embodiment of the invention, or from the following description of said embodiment, or will be otherwise evident to those skilled in the locomotive art.

Brief description of th drawings or only fragmentarily shown;

Figure 2 is a vertical transverse section through the fire-box of the locomotive, looking rearwardly therein, taken approximately on the line 2-2 of Figure 1a, but to a larger scale, and showing in elevation the locomotive cab and in section the running boards at each side and the insulation upon the outside of the fire-box, which latter are omitted from Figure 1a;

Figure 3 is a vertical transverse section, looking forwardly in the fire-box, taken approximately on the line 33 of Figure 1a, and drawn to the same scale as Figure 2, this view omitting any showing of the main banks of boiler tubes which are located forward of the combustion space;

Figure 4 is a similar transverse vertical section, but omitting the external insulation taker approximately on the line 4-4 of Figure 1a, this figure being in the region of the secondary combustion space;

Figure 5 is a similar transverse vertical section.

to the same scale as Figures 2, 3 and 4, taken through the main part of the boiler, approxiery will maintain water in allthe tubes of the boiler even upontotal failure of the circulating Dump equipment.

Various miscellaneous objects and advantages of the invention, relative to boiler construction and operation, are: the increasing of the heat.- ing surface within given volume and weight limitations; reducing the velocity of the gases of combustion; reducing the volume and weight of water required to be maintained in the boiler, per unit of steaming capacity, to such an extent that the total weight of the locomotive in working order (exclusive of tender) may be substantially reduced below that of existing locomotives of equal capacity; eliminating conventional boiler braces, fiat water-legs, stay-bolts and crown sheets with their hazards; minimizing the swash or water in the boiler; widening the gauge limits between the high water level and low water level of the boiler; increasing the flexibilit of.

boiler operation to respond more readily to the wide fluctuations in steam demand; providing for ready removability 0f superheater elements without disturbing, stack and nozzle castings or steam P pes to the cylinders; lowering the center of gravity of the locomotive; and generally arranging the locomotive structure in such manner that the enclosing shell, the boiler elements associated therewith, the. cab and the auxiliaries can be handled as a rigid unit, for unitary removal from and replacement upon the main frame.

There are still other objects, advantages and novel features of the present invention, both mately on the line 5--5 of Figure la, showing in elevation one of the water and steam drums at each side of the locomotive, this figure also omitting the insulation but illustrating certain parts of the external bracing especially adapted for the support of insulation and for the mounting of external sheathing;

Figure 6 is a similar transverse vertical section. through the smoke-box of the locomotive, taken approximately on the line 8-6 of Figure 1b, looking rearwardly in thesmoke-box toward the main portion of the boiler but showing only a 'few 01 the tubes in the main banks of boiler tubes, this figure illustrating in elevation the major water inlet and outlet headers at the front end of the boiler, but omitting certain of the bracing parts shown in Fig. 5.

Figure 'l is an irregular plan section through the smoke-box and a portion of the boiler, taken about on the line 1-1 of Figure 1b, but to a larger scale;

Figure 8 is. a detail section through the Joint between a water inlet header and one of the boiler tubes fed therefrom, and showing a suitable means for restricting the flow arcs, of the tube inlet whereby a pressure drop between the header and the tube is assured in order to secure the prope distribution of water circulation throughout the various tube units of the boiler;

. Figure 9 is a detail vertical section through the upper end of one ofthe water and steam drums,

showing the water inlet and steam outlet connections; a Figure 10 is a plan section talren on the line iii-ill of Figure 9 and showing also the water outlet connection adjacent the bottom of the drum; and

Figure 11 is a right side elevational view of the complete locomotive (excepting the tender),

showing the running gear diagrammatically, and illustrating, in section only, most of the streamline covering of the locomotive and the insulation retained thereby.

Description of structure In this description, unless otherwise qualified by the context, the following terms will be employed in the senses here indicated: the word locomotive will not include a separable tender which normally carries the fuel and water supply; the term "pressure-free" means substantially free from direct subjection to the boiler pressure; the word foundation" denotes broadly the main rigid structure or basic strength structure of the locomotive which is carried and propelled by the running gear, or denotes more specificallya main frame (that may include a cylinder casting, etc.)

which largely takes the pulling and buffing stresses, together with a shell which is fixed thereto and houses the steam generating means; and the term running-gear comprises wheels. axles, boxes, springs, spring rigging, driving and connecting rods, valve motion work, etc.-

Reference will first be made to t e general views of the locomotive, Figures 1a, and 1b together, and Figure 11.. Considered in a general way, the locomotive comprises: a longitudinally extending main frame 11; a longitudinally extending metallic structural shell is, which, though housing much of the boiler structure, is pressure-free and is to that extent'functionally independent of the boiler, said shell preferably extending throughout most of the length 01' the locomotive and serving as a major element of the foundation; steam generating means which chiefly comprise a multiplicity of water tube elements housed within said shell (the main body of said tubes being indicated generally by the reference character it in Figure 1b); and running-gear, the main wheels of which are desig nated by the reference character 22.

The structural shell I8, which houses the evaporating means of the boiler but is substantially. independent thereof as to the pressure function, forms a major element of strength of the locomotive; and, although 'it is preferably so constructed, and removably mounted on the frame N, that it (the shell) with the other associated boiler parts may be handled as a unit'separately from the frame II, it may be considered structurally as an integralrpart of the locomotive extending all the wayback to the front end of the fire-box proper, there being a plate 44 spaced above said bottom plate and extending back to the front end of the secondary combustion cham her; said plate 44 serving as the bottom wall of the passage-way for the products combustion, in other words as the bottom wall of the metallic shell which encloses the evaporating means. In the region of the secondary combustion chamber, said plate 44 slopes upwardly, as seen at 44a in Figure la and Figure 4, to a juncture with the transverse vertical wall 45 at the front end of the fire-box proper.

In the region of the fire-box, the main longitudinal girders 39 are interconnected by transverse bottom braces 46 at the front and rear ends of the fire-box (as shown in Figure 1a), and are braced along the sides of the fire-box by heavy angle bars 4? (as seen in Figures2 and 3).

The major part of the metallic shell is built Figures 2 and 3 by the reference character ll!) foundation, when secured "in position on the frame 91. I l I The base of the shell, in the embodiment shown, is formed of main longitudinal girders 39, of considerable vertical depth (as seen in most of the figures of the drawings), extending sub; stantiaily throughout the length of the locomotive (as seen in Figure 11), one such girder being adjacent each side of the locomotive, and the two girders being interconnected at intervals, from the front end thereof back to adjacent the region of the secondary combustion space, by means of transverse I-beams or other structural members. 40 (see Figures lb, 5 and 6), the interconnection of the parts being by any suitable means such as angle members 4| and rivets "42. Throughout the same region, the longitudinal girders are interconnected by a bottom plate 43v cover 58.

extends upwardly from the base member 41 at one side, completely across the crown of the firebox space, and down on the other side to the base member 41, the rear of the fire-box enclosure being completed by a back plate 49 (Figures 1a and 2). In the region of the secondary combustion chamber, the top wall of the shell slopes slightly downwardly and forwardly (as shown at 68a in Figure 1a), and the side walls 48b (Figure 4) slop toward each other in the forward direction, to merge with the side walls 480 of that portion of the shell which encloses the major banks of boiler tubes (see Figure 5).

Thus the shell is widest in the region of the fire-box, i. e., from the rear end up to the transverse fire brick wall 50 (Figure la). From thence forwardly, throughout the region of the second ary combustion chamber, i. e., throughout the extent of the sloping bottom wall Ma (Figure 1a,), the side walls progressively come closer together (as indicated at Mb in Figure 4); and throughout the region from the front of the secondary combustion chamber forwardly to the smoke-box, the spacing between the side walls 480 of the shell is relatively closer, as shown in Figure 5. This provides the necessary space exteriorly of the shell, at each side, for the row of water and steam drums 5|, shown in full lines in Figure 11 and in the sectional views of Figures 5, 6 and '1. and shown in dotted lines in Figures la. and 1b.

In the region of the major part of the boiler, just described, the side walls 48c, instead of being continuous with the top wall (as in the firebox) terminate at their upper ends and are there reinforced by suitable members such as the bar stock 52 seen in Figure 5; and in this region the roof or top wall is made up of a removable cover a second removable cover plate 53a (see Figure 1b).

From about the plane of the line 6-6 of Figure 1b forwardly to the front end of the smokebox, the side walls 48d (see Figure 6) are again continuous with the top wall. as in the case of the fire-box wall structure 48; the top of the smokebox shell being, however, depressed forwardly of the stack 55, to form a recess We (see Figure lb) to receive any suitablefeed water heater 56 (see Figure 11). The front end of the smoke-box may be closed by a plate 51 and a removable for applying crumpled aluminum foil indicated at T2 in Fig- The structural shell is completed by the following parts: in the region of the fire-box (as 'seen in Figures 1a, 2, 3, and 11) there are I-beams 64 at intervals, extending-circumferentially upon the outside of the shell 48; and longitudinal I-. beams and Z-bars 65 and 66 interbracing the same.. Similar bracing structure 61 is located at the back sheet 49. In the region of the secondary combustion chamber, the forwardly converging side walls 48b, seen in Figure 5, are reinforced by the header boxes 68, shown in Figures 4 and 11 (later to be described in detail, with reference to the boiler elements). In the main boiler region, forward of the secondary combustion chambenthe side walls 480 are braced by vertical flange members 99 and flanged triangular bracing sheets I (see Figures 5, 6, 7 and 11) Additional flanges 69a may extend outwardly from the side walls and down to the base (Figure while the cover plates 53 and 53a, which are flanged at 53, may also carry arched flanges 69b by means of vertical transverse sheets 690. In addition, the steam and water collecting and storage means, preferably in the form of the vertical drums 5| as herein shown, serve to add to the strength and stiffness of the shell, by being mounted rigidly, as by the base brackets II, upon the lateral extensions of the base of the shell, andby being secured firmly to the side walls of the shell, as at Ha.

The various external bracing and stiffening members of the shell, just described, serve two further functions: First. they prgvide a space insulating materials, such as ures 2, 3 and 11; and second, they provide .a means of support and of fastening for the thin external metallic wrapper or covering 13 which is placed over the insulation. The latter metallic covering or sheath can be readily supported, for example upon the transverse inverted U-shaped I-beam braces 64 at the fire-box zone, by the flanging 691) on the cover plates,- by the flanges 69a projecting from the side walls, and even by the outer sides of the steam drums 5i themselves, such sheathing if desired being merged with a sloping streamline nose portion 13a which may be secured to the bumper beam 20. Similarly, the piping beneath the running boards 15 may be suitably insulated and enclosed by suitable sheathing 131) (Figure 5). It will be observed from Fig. 11 that the nose sheath 13a encloses various parts, including thev pumps I53,

but the latter ,are still free from subjection to the excessive heat of the products of combustion, as thei are located outside of the shell I8.

By comparing the several cross sectional views (Figures 2 to 6 inclusive) it will be seen that when looking forward from the cab windows I4, the engineer and fireman have a clear vision ahead.

It will also be seen that the available space at each side is such as to accommodate extra-wide running boards I5, which. may be thus extended, at substantially uniform width, in a straight line from the front of the cab to the front end of the locomotive. These running boards are conveniently mounted upon the flanges of the triangular brace plates ID, by means of any suitable brackets 16 (see Figure 5), which also serve to support the main water delivery pipes ll of the boiler circulating system; these pipes, together with the main water return pipes I8 from the driuns 5|, being conveniently located in the space beneath the running boards, the return pipes 18 being mounted by any suitable brackets I9 upon the main longitudinal girders 39 of the base of the shell (see Figure 6).

Features of the boiler Referring now to the steam evaporating means, it will be observed that the shell structure 48 in the-region of the fire-box is lined with a multiplicity of water tubes of relatively small diameter.

The side walls of the primary combustion space, from the bottom thereof up to the top of the front refractory wall 50, are covered by tubes 90,

wall of the fire-box (as seen in Figures 1a and 3) then transversely, half-way across the back wall of the fire-box (as seen in' Figure 2), where it doubles back upon itself at 99c and retumsto the front end of the box. Obviously, a tube unit may include one or more such return passes, or sinuous bends. At the point of the bends, as well as elsewhere if necessary, fins 93 are provided, in order not to leave too large an area of the structural shell unprotected from the direct heat of the products of combustion.

The remaining tubes lining the side walls of the fire-box; i. e., those lying above the level of the transverse brick wall, designated herein as tubes 94, are similarly disposed with reference to the side and back walls of the fire-box (as is seen in Figure 2), the transverse pass thereof being shortened, however, to accommodate the flne' door opening 95. The front ends of these sidewall tubes extend into' what may be termed a,

which region their inlet ends 94a extend out through the side walls 48b of the shell (see Figure 4) for connection to the vertical delivery headers 91 (see Figures la and 11). The outlet ends 941; of said tubes similarly extend laterally through the shell and are connected to the vertical return headers 98, one at each side of the secondary combustion chamber. Some of these tubes 94 have return bends both at their front and at their rear ends, and may be pro: vided with fins similar to those hereinbefore mentioned.

The front wall of the fire-box, i. e., up to the top of the transverse brick wall I0, is lined with water tube units 99 (see Figure 3), which have their inlet and outlet ends extending through the wall 45, with connections (not shown) coupling them up to the aforementioned headers 9| and 92.

The roof of the fire-box is lined with tube units I09 (see Figures 1a and 3) which at their rear ends are bent downwardly (as seen in Figures la and 2) and there have return bends I900, as shown. Their inlet ends Illfla are variously coupled to longitudinal headersv "II or the connected cross-header I92 which (as seen in Figure 4) is coupled to the upper ends of the vertical delivery headers 91. The outlet ends lflllb are coupled to the longitudinal return headers I04 or to the laterally extending return headers I04.

' The transverse return headers I04 are connected into main junction members I05 (see Figures 1a, 4 and 11) which also receive the discharge from the upright return headers 98, said junction members I05 being connected through the pipes and elbows I06 and I! to the main return line I08 delivering through branches I09 to the steam releasing drums i.

Referring againto the fire-box, the arch tubes H0 are coupled at their lower (forward) ends to the delivery headers M by means of specially angled headers iii. At the upper rear portion of the fire-box these arch tubes IIO bend laterally (as seen in Figures 1a. and 2) and thence extend forwardly along the side walls of the firebox near the top thereof, and pass out through the shell and have their discharge ends IlOb coupled to the vertical receiving headers 98 (see Figure 4).

Above the arch, and extending forwardly to the front of the secondary combustion chamber (i. e., to a point about mid-way between the section lines 6-4 and 5-5 of Figure 1a), are four series of upstanding tube units H2, providing five lanes or paths M3 for the products of combustion (see Figures 3 and 4). Some of these tube units have their inlet and outlet ends I IZa, IiZb coupled respectively to the longitudinal delivery and discharge headers till and I03, in the manner shown in Figures la, 3 and 4. Others have their inlet ends coupledto the transverse delivery header tit and their outlet ends coupled to the longitudinal discharge headers 92, located below the sloping bottom sheet Ma beneath the secondary combustion chamber. The rows of tube units H2 are disposed substantially-in vertical alignment with the arch tubes, and add materially to the evaporating surface in the secondary combustion chamber. It will be observed that in Figure 1a some on these tubes have been broken away to show the side wall tubes. It may here be mentioned that the two header boxes 68 are primarily a means of strengthening the side walls of the shell in the region of the secondary cornbustion chamber, where said shell has a multiplicity of apertures to permit the connections from the fire-box tubes to pass thenethrough. The boxes 58 also form closures against air leakage where the tubes pass through the shell. These header boxes may be made as castings or of any other suitable rigid construction.

The bottom, sloping, wall 56a of the secondary combustion chamber is covered by a series of tube units M5, which are actually the rear ends of the floor tubes extending throughout the major portion of the length of the shell. These tubes, as seen in' Figure it, have their inlet ends shell structure (as seen in Figure 5) are protected by finned tubes H3, which extend from adjacent the smoke-box back to the region of the secondary combustion. chamber, whereat they have return bends injuxtaposition to the return bends of the side wall tubes of the fire-box (as seen in Figure 1a,). The side wall tubes have their inlet ends Ilfla coupled to vertical headers i it (as seen in Figure 7) and their discharge ends IIOb coupled to vertical headers lit. 7

The roof tubes, for the main body of the boiler, are divided into two general groups, 1. e., tubes 52! on, the inner face of the cover plate 53, and

tubes I22 on the inner face of the cover plate 53a (as seen in Figures 1a, lb and 5). The tubes IZI have their inlet ends coupled to a cross header I23 and their outlet ends coupled to the cross header I24. The tubes I22 have their inlet ends I22a coupled to a header I25 extending half-way across the top of the shell (see Figure 6) and their outlet ends I22b coupled to a similar cross header I26.

The roof is completed by a. superheater header structure M, the superheater elements I21 extending from the region 5t (Figure 1b) to the region just forward of the secondary combustion chamber (Figure 1a), the rear return bends I2'Ic of the superheater elements being shielded by a series of short vertical water tube units We having their inlet ends coupled tothe cross header I29 and their outlet ends to the cross header IN.

The main bulk of the convection surface of the steam generating means is composed of the tube bundles generally indicated at I9 in Figure lb and in Figure 5. The tubes in these bundles are coupled up to the various cross delivery headers E30 and the cross discharge headers I3! (see Figures lb, 6 and 7); it being here noted that Figures 1a, 1b, 5 and 7 are the only figures showing the full banks of these tubes. The said main banks of tubes I9 are omitted entirely from Figures 3 and 4 inorder not to confuse the same, since the tube banks are actually located ahead of the planes on which Figures 3 and 4 are taken. Only a few of the tubes I0 are shown in Figure 6, but it will be understood that all of the front ends of aid tubes would be seen in elevation when looking in the direction of that figure.

It will be observed that, for the most part, straight longitudinal paths are provided for the passage of the products of combustion from the fire-box to the smoke-box, thus reducing to a minimum the scouring of the tubes by the cinders. Even in the fire-box itself, the tubes which line the walls thereof are substantially parallel with the pathof the fuel and flame stream.

Various tube fastening means may be employed to secure the tubes against vibration. Several such are described and claimed indivisional application Serial No. 456,010, filed August 25;

It will now further be observed that the tubes are disposed primarily for convenience of installation and removal, and for ease of making external connections to the internally housed tubes, rather than to facilitate natural circulation. In fact, with the sinuous tubes herein employed, efiective natural circulation would be impossible. For this reason, and others hereinafter to be referred to, we have provided a forced-feed water circulation, from the delivery headers to the tube units, and thence returnin through the discharge headers. This mechanism will be described later. In order, however, to assure a suitable pressure head between the delivery headers and the tube units, restrictions can be placed in the inlet ends of the tubes, as shown in Figure 8.

As typical of the tube units generally, the tube I9 whereit enters the delivery header H0, is provided with a plug member ME having a restricted orifice Hill, so as to assure the necessary pressure drop. Elements having orifices Id? of difiering sizes can be employed in different tubes, in order to secure the desired distribution of the circulation; and if tests indicate the need for changes in circulation an orifice of one size may be substituted for one of another size. Th external plug Mill provides a means for access to tubes may be employed.

The boiler circulation Turning now to the circulation of the boiler, which is indicated generally byarrows, it will be seen from Figure 11 that the feed water from the source of supply (such as the tender) is normally taken by way of the pipe I46, by means of pump 63, which delivers the feed water through the pipe I50 to the feed water heater 56 (the details of which need not be herein shown, as any suitable feed water heater may be employed), and from the feed water heater the pipe II delivers through check valve I52 into the discharge line I! from one of the circulating pumps I53. The two lines H are the main water delivery lines from the pumps, and'each has a check valve I56 to prevent return flow through the particular pump in the event said pump should fail. The check valves I54 also retain the water in the tube coils above the water level in the drums 5i.

The two delivery lines 11 are cross-connected by the branches Ila, the vertical headers or pipes I55 and the crossheaders I30 (Figure 6) also by the upwardly extending pipes [23a and crossheader I23 (Figure 5) and the pipes I5? and cross header H6 (Figure 7). Adjacent the rear of the boiler they are further cross-connected by way of the lateral pipes I56, vertical pipes or headers 97 and crossheaders Hi2 and H4 (Figure 4). The water delivery system includes various other branch pipes and connections, such as I58 (Figure 7), I59 (Figure 1a), and Ia (Figure 122). It will be evident that all of the tube units, hereinbefore described in detail, are fed from this main system.

' steam generating tubes will always exist.

example, but not by way of limitation, a differential of about 35-40 lbs. may be employed).

The discharge from the various steam generat- I60 and I24 (Fig. 1a), and adjacent the front by means of the elbows I08a, the vertical pipes or headers I6I, and the crossheaders I3I (Fig. 6). Other dischargeconnections into this line are shown at I62 (Fig. 7). From the main discharge.

lines I08, the branch lines I09 deliver into the collecting and storage drumsBI, preferably tangentially, by means of the seen in Figures 9 and 10. r

From the bottoms of the drums, branch pipes I63 deliver water into the main return-lines I8 which go to the intake side of the pumps, by way of the cross-connection I64 (Fig. 'l) and the two branches Ifla. 1

The steam is released within the drums, and passes out through the traps. I65 (Figs. 9 and 10) to the steam branch pipes I66, which in turn deliver into the main longitudinal steam pipe or manifold I61. The said manifold, at each side of the locomotive, delivers through a steam header I60 into thesuperheater header 54. After passing through the superheater units, the su-' perheated steam is delivered from the superheater header through the steam pipe let to the valve chests (there pelvic any suitable throttle valve,

curved pipes l09a not shown, in the superheater header, in accordance with standard practice).

It should be understood that the pumps, which may be of any suitable available type, are so chosen that they circulate the water preferably several times as fast as evaporatl takes place, for example, a circulation of eig t times the evaporation. If each pump is of a maximum capacity equal to about three-quarters offlthe total desired circulating capacity, they can be normally operated together at about two-thirds of maximum rating. In the event that one pump should fail, the other could still give ample circulation, and even if the remaining pump was in such a condition of wear that it could only pump a fraction of the intended 8 to 1 circulation, it would prevent burning out of the boiler.

It is further desirable that the pumps should develop a pressure sufliciently above the normal boiler pressure that a pressure drop through the orifices between the'water inlet headers and the (As an In this way, the tubes are maintained substantially full of water, and the steam is released largely in the drums, which, standing -ver tically, give considerable leeway for fluctuation of the water level therein, without risk of the boiler running dry since there is a forced circulation through the tubes regardless of the water level in the drums.

In the event of total pump failure, circulation -can still be eifected by means of the injector 62,

taking water through the line I10, and delivering by way of pipe Ill and check valve I12 into the main feed line Tl, preferably adjacent the back end thereof, but in any event at a point such that the other check valves I52 and I54 will prevent feed water from the injector going back to the pumps or to the feed water heater.

Typical example of general results secured by the construction herein disclosed For purposes of comparison, let us consider for the moment a typical locomotive of ordinary firetube boiler construction, say of the 4-8-4 type, having a weight of about 477,000 pounds (exclusive of tender), operating at300 pounds boiler pressure, having a grate area of square feet, a fire-box volume of about 600 cubic feet, a heating surface of about 5500 square feet, a minimum gas passage flow area of about 1400 square inches, and rated at about 80,000 pounds of steam per hour. In such a locomotive, the complete steam generating plant, i. e., fire-box and boiler barrel with water and steam therein, tubes, fiues, superheater, smoke-box, steam pipes, lagging and jacket, weighs about 184,000 pounds.

A locomotive constructed according to the present disclosure, in external proportions similar to the ordinary locomotive just referred to, and within the same clearance and weight limitations, and having the same grate area, would' have about 800 cubic feet of fire-box volume, about 6300 square feet of heating surface, and about 1600 square inches minimum cross sectional area of the gas passage, and even if operated at the same boiler pressure (300 pounds) would produce close to 100,000 pounds of, steam per hour, in addition to which there would be a reduction in the velocity of the products of combustion, reducing cinder scouring, and improved combustion.

Viewed in another way, the comparative loco-.

motive of the present disclosure, if made to have a steaming capacity similar to the typical ordinary locomotive, will weigh less, for example,

about 453,000 pounds as against about 477,000-

pounds (still assuming the same boiler pressure).

example, a drum storage capacity of about 8000 pounds even though the drums are of relatively small diameter (and can therefore be made of relatively light weight), but since they stand upright the water level can vary through about 30 inches of height. In the ordinary locomotive just referred to, when working at full capacity and no feed water is being pumped into the boiler, the water level will recede from the maximum water level down to the lowest gauge cock (which is the minimum safe water level) in about /2 minutes, the maximum and minimum gauge limits being only about 6 or 7 inches apart, compared with about 30 inches'in the present case. Even if the capacity of the drums of the instant case provides only the same time interval (i. e., 5 minutes) between maximum and minimum permissible water levels, much less accuracy in reading the gauges is required.

It should also be pointed out that the present arrangement results in substantial flexibility in design, and permits a lowering of the center of gravity of the locomotive (since there is no crown sheet and no large volume of water to be maintained above such a crown sheet), and the use of a plurality of small drums also permits variation in the designwith respect to longitudinal location How the various other objects and advantages referred to in the beginning of the specification are secured will be evident without further elaboration. It should also be understood that. in carrying out the broad principles of the invention, many variations in detail may be made, and further that any proportion s, numerical values, and the like, stated herein, are for purposes of illustration only and are not intended as limitations.

We claim: 1. In steam locomotive construction, a pressure-free shell extending lengthwise of the locomotive and forming a passage for a heating medium in its traverse from the zone of combustion to an outlet zone,a multiplicityof steam generating units of a plurality of different configurations housed within said shell in different positions for substantially differing subjection to the heating medium, steam and water collecting means, water circulating pump means located out of the direct path of the heating medium, parallel water delivery lines from the pump means to said units, discharge lines from said units to said collecting means, parallel water return lines from said collecting means to said pump means, a. steam take-ofi system from said collecting means, and means for assuring adequacy of the pump circulation in all said units regardless of the dif- :ferences mentioned.

2. In steam locomotive construction, a pressure-free shell extending lengthwise of the locomotive and forming a passage for a heating medium in its traverse from the zone of combustion to an outlet zone, a multiplicity of steam generating units comprising forced circulation water tubes of a plurality of different configurations housed within said shell in different positions for substantially differing subjection to the heating medium, steam and water collecting drums, water circulating pump means located out of the direct path of the heating medium, parallel water delivery lines from the pump means to said units,

discharge lines from said units to said collecting means, parallel water return lines from said collecting means to said pump means, a steam take- I ofi system from said collecting means, means for assuring adequacy of the pump circulation in all said units regardless of the differences mentioned, in which construction some of said units constitute the high point of the locomotive boiler, and check valve means are provided in the water delivery system from the pump means to the generating units adapted to prevent drop in water level in said units.

3. In steam locomotive construction, a pressure-free shell extending lengthwise of the locomotive and forming a passage for a heating medium in its traverse from the zone of combustion to an outlet zone, a multiplicity of steam generating units of a plurality of different configurations regardless of the differences mentioned, in which construction means are provided for taking feed water from a source of supply and having 8, normally open feed connection into a water delivery line between the pump means and the generating units.

4. In steam locomotive construction, a pressure-free shell extending lengthwise of the locomotive and forming a passage for a heating medium in its traverse from the Zone of combustion to an outlet zone, a multiplicity of steam generating units of a plurality of different configurations housed within said shell in difierent positions for substantially differing subjection to the heating medium, steam and water collecting means, water circulating pump means located out of the direct path of the heating medium, water delivery lines from the pump means to said units, discharge lines from said units to said collecting means, water return lines from said collectingmeans to said pump means, a steam take-off sy tem from said collecting means, and means for assuring adequacy of the pump circulation in all ter return lines each comprise a plurality of main conduits in parallel, there being cross-connections between the parallel conduits of each set.

5. In steam locomotive construction, a pres-.

direct path of the heating medium, water delivery lines from the pump means to said units, dis charge lines from said units to said collecting means, water return lines from said collecting means to said pump means, a steam take-off system from said collecting means,- and means for assuring adequacy of the pump circulation in all said units regardless of the difierences mentioned, in which construction the steam and water collecting means are disposed at each side of the locomotive.

6. In steam locomotive construction, a pressure-free shell extending lengthwise of the locomotive and formin a, passage for a heating medium in its traverse from the zone or combustion to an outlet zone, a multiplicity of steam generating units of a plurality of difierent configurations housed within said shell in difierent positions for substantially difiering subjection to the heating medium, steam and water collecting means, water circulating pump means located out of the direct path of the heating medium, water delivery lines from the pump means to said units, discharge lines from said units to said collecting means, water return lines from said collecting means to said pump means, a steam take-ofi system from said collecting means, and means for assuring adequacy of the pump circulation in all said units regardless of the differences mentioned, in which construction the steam and water collecting means are constituted by drums located at each side of the locomotive.

7. In steam locomotive construction, a pressure-free shell extending lengthwise of the locotions housed within said shell in different positions for substantially differing subjection to the heating medium, steam and water collecting means, water circulating pump means located out of the direct path of the heating medium, water delivery lines from the pump means to said units, discharge lines from said units to said collecting means, water return lines from said collecting means to said pump means, a steam take-off system from said collecting means, and means for assuring adequacy of the pump circulation in all said units regardless of the differences mentioned, in which construction the water delivery and water return systems. each comprise main conduits disposed at each side of the locomotive, and headers lying substantially in transverse planes are provided to connect said main conduits to various 01 the steam generating units. 4

9. In steam locomotive construction. a pressure-free shell extending lengthwise of the locomotive and forming a passage for a heating medium in its traverse from the zone of combustion to an outlet zone, a multiplicit of steam generating units of a plurality of different configurations housed within said shell in diiferent positions for substantially diifering subjection to the heating medium, steam and water collecting means, water circulating pump means located out of the direct path of the heating medium, water delivery lines from the pump means to said units, discharge lines from said units to said collecting means, water return lines from said collecting means to said pump means, a steam take-off system from said collecting means, and means for assurin adequacy of the pump circulation in all said units regardless of the difi'erences mentioned, in which construction means are provided for taking feed water from a source of supply and having a normally open feed connection into a water delivery line between the pump means and the generating units, and means for preventing back flow through the feed water line.

10. In steam locomotive construction, a pressure-free shell extending lengthwise of the 10- comotive and forming a passage for a heating medium in its traverse from the zone of com- I bustion to an outlet zone, a multiplicity of steam motive and forming a passage for a heating medium in its traverse from the zone of combustion to an outlet zone, a multiplicity of steam generating units of a plurality of different configurations housed within said shell in difierent positions for substantially differing subjection to the heating medium, steam and water collecting means, water circulating pump means located out of the direct path of the heating medium, water deliver lines from the pump means to said units, discharge lines from said unit to said collecting means, water return.1ines from said collecting means to said pump means, a steam take-01f sys-=,

tem from said collecting means, and means for assuring adequacy of the pump circulation in all said units regardles of the differences mentioned, in which construction the steam and water collecting means are constituted by a longitudinally extending series of drums located at each side 01- the locomotive, the drums of each row being connected in parallel to the discharge lines, return lines and take-oil system.

8. In steam locomotive construction, a pres sure-free shell extending lengthwise of the locomotive and forming a passage for a heatin medium in its traverse from the zone of combustion to an outlet zone, a multiplicity of steam generating units of a plurality of different configuragenerating units of a plurality of difierent configurations housed within said shell in different positions for substantially differing subjection to the heating medium, steam and water collecting means, water circulating pump mean located out of the direct path of the heating medium, water delivery lines from the pump means to said units, discharge lines from said units to said collecting means, water return lines from said collecting means to said pump means, a steam takeoff system from said collecting means, and means for assuring adequacy of the pump circulation in all said units regardless of the differences mentioned, in which construction the water delivery and water return lines each comprise a plurality of main conduits in parallel, there being crossconnections between the parallel conduits of each set, and wherein the pump means comprise a plurality of pumps each delivering to a main delivery conduit and receiving from a main return conduit, whereby, in conjunction with the crossconnections, the operation of asingle one 01' the pumps will circulate water through all the essential elements of the system.

11 In steam locomotive construction, a pressure-free shell extending lengthwise of the 1000 motive and forming a passage for a heating medium in its traverse from the zone of combustion to an outlet zone, a multiplicity of steam generating units of a plurality of different configurations housed within said shell in difierent positions for substantially difiering subjection to-the heating medium, steam and water collecting means, water circulating pump means located out of the direct path of the heating medium, water delivery lines from the pump means to saidunits, discharge lines from said units to said collecting means, water return lines from said collecting means to said pump means, a steam take-01f system from said collecting means, and means for assuring adequacy of the pump circulation in all said units regardless of the differences mentioned, in which construction the water delivery and water return systems each comprise main conduits disposed at each side of the locomotive, the main conduits of each set being connected in parallel, and headers lying substantially in transverse planes are provided to connect said main conduits to various of the steam generating units.

12. In steam locomotive construction, a pressure-freeshell extending lengthwise of the locomotive and forming a passage for a heating medium in its traverse from the zone of combustion to an outlet zone. a multiplicit of steam generating units of a plurality of difierent configurations housed within said shell in dlflerent positions for substantially differing subjection to the heating medium, steam and water collecting means, water circulating pump means located out of the direct path of the heating medium, water delivery lines from the pump means to said units,

discharge lines from said units to said collecting means, water return lines from said collecting means to said pump means, a steam take-oil system from said collecting means, and means for assuring adequacy of the pump circulation in all said units regardless of the differences mentioned, in which construction the water delivery and water return systems each comprise main conduits disposed at each side of the locomotive, the main conduits of each set being connected in parallel, and headers Lying substantially in transverse planes are provided to connect said main conduits to various of the steam generating units, the headers being utilized as cross-connections between the parallel conduits.

WILLIAM E. WOODARD.

ARTHUR H. F'ILANDER'. 

